The unseasonably warm weather in Denver early this year lured irises, daffodils and other perennial flowers out of their winter slumber weeks early.
Trees, not knowing the calendar date, began to bud in early March. In Denver and across much of Colorado, temperatures remained unseasonably warm for months. And precipitation? Hard to come by.
By early March, , and one-tenth of the state suffered extreme or exceptional drought, including Denver and its surrounding areas. The conditions did not bode well for gardens this year.
For home gardeners, protecting trees, shrubs, flowers and produce means paying careful attention to watering routines and shielding as much water as possible from evaporation, experts said.
“It has been such a warm and dry winter — things seem to be way ahead of schedule,” said Chris Hilgert, the director of and a horticulture specialist at Colorado State University Extension.
Here are some tips from experts for gardeners looking to help their greenery survive drought.
Smart watering
If you didn’t water your trees this winter, it’s better to start late than never.
In a dry winter, trees need deep watering to stay healthy, said Jennifer Miller, the assistant manager of horticulture at the . Evergreen trees especially need the extra moisture because they keep their needles all winter and lose water to evaporation through their leaves.
“Trees are the biggest plants out there, and we don’t want them going into the growing season stressed,” Miller said.
Trees benefit from deep watering. Established trees should be watered around the perimeter of their canopy, as that’s where their roots reach. Once or twice a month, a tree needs approximately 10 gallons of water per inch of trunk diameter.
Younger trees — a year old or younger — should be watered near their trunk, as their roots have not yet grown out as far. They need about a gallon of water, Miller said.
Miller uses 5-gallon buckets with holes drilled in the bottom to water her trees. She measures out the water and then places the buckets around the trees’ canopy lines, letting it drip down.
Be careful to water only when temperatures are above 40 degrees and the ground isn’t frozen, she said. Water can’t pass through frozen soil and won’t reach the roots.
Preventing evaporation
Once planting season comes around, gardeners’ primary challenge becomes minimizing evaporation.
The closer to the roots you apply water, the better, Hilgert said. Using a drip line reduces the amount of water lost to wind and evaporation.
Miller’s top tip is mulch — and then more mulch.
“I can’t stress mulch enough; it’s going to be your best investment,” she said.
Mulching around plants, trees and shrubs helps soil retain moisture, reducing the need to water.
Another simple solution? Weeding. Removing weeds from your garden leaves more water for the plants you are trying to grow, Miller said.
A garden’s water needs will depend on the specific plants, but Miller recommends watering one to three days a week for 30 minutes to an hour. Poking a finger into the soil is a good test to determine if more water is needed. If the soil is dry a few inches down, it’s time to water.
Grouping together plants that have similar water requirements can help reduce water waste.
It’s also important to water during the cooler hours of the day to minimize evaporation. Miller recommends watering between 5 a.m. and 9 a.m. or, if that’s not possible, in the late afternoon or early evening.
Watering in the evening, however, can increase the risk of fungus, as the moisture sits on the plants’ leaves and stems longer, she said.
While planning your spring planting, don’t forget the birds and the bees, Miller said.
She suggested installing a water fountain or a bird bath to attract the important species to your yard. Leaving a few pieces of floating wood in the water can give bees a place to land while they take a drink, she said.
Smart plant choices
Gardeners can also prepare for drought in the long term by shifting toward , Miller said. Plants adapted to semi-arid climates, where temperatures can fluctuate widely, will do well with minimal human intervention.
Many Colorado seed companies sell varieties of flowers, vegetables and fruits that are adapted for Colorado’s climate, she said.
Hilgert also suggested swapping out thirsty nonnative lawn turf for more resilient native grasses, like or
While gardeners may be tempted to start planting early, Hilgert warned that cold snaps and snow are still possible through the end of April.
“Winter may still show up temporarily,” he said.
